Observations on the bivalves Montacuta substriata and M. ferruginosa, ‘commensals’ with spatangoids

Abstract

Field and laboratory observations were made of the erycinacean bivalves Montacuta substriata and M. ferruginosa, which are usually considered as ‘commensals’, respectively, with the burrowing spatangoids Spatangus purpureus and Echinocardium cordatum. These species were obtained mainly from the Plymouth area, where M. substriata was also found with E. flavescens and E. pennatifidum, and also very occasionally with E. cordatum. Similarly, M. ferruginosa was also found with 5. purpureus, E. flavescens and E. pennatifidum. This indicated that the associations are not as specific as had been thought.